| The emergence and development of industrial robot is the result of the multi-discipline comprehensive. With the reference of paperless manufacturing technology, off-line programming technology, rapid prototyping technology and digitalization technology in the assembly manufacturing, the procedure and method of processing have been changing. The application of industrial robot in mechanical processing field causes lots of research units and scholar’s attention. The system of the6-DOF industrial robot has a low stiffness and is difficult to meet the requirements of metal cutting processing. The principle of cutting processing on ER50-C20robot were studied and verified.1. The method of D-H had been applied to establish the kinematics equation of robot. This study had inferred and verified inverse kinematics and had calculated the Jacobian matrix of robot in vector product.2. In this paper, the terminal hand of robot which joints with motorized spindle were designed and coordinate change matrix between base coordinate frame and terminal milling cutter coordinate frame were established. Using Newton-Euler equations establishes the relationship between cutting force and generalized force of robot joints.3.The equivalent stiffness were calculated according to the structural parameters of transmission part of robot and joint stiffness were gained by converting elastic component simplified by transmission part into corresponding joint. The performance of joint deflection in the terminal of the robot were mapped out through the Jacobian matrix. The deflection deformation model of stretch, reverse and bend were established by considering robot arm-bar as flexible links and the kinematics model contained error parameters of robot were established. The mapping of micro variable of arm-bar deflection at the end of operation were calculated. Finally, through the superposition of joint deflection and arm-bar deflection, the total stiffness of operating space were calculated by defining stiffness.4. The deviation of B-B triangle pitch produced in the process of cutting machining due to the deflection deformation of the terminal of the arm-bar. An example is given to demonstrate the feasibility of robot stiffness model to error compensation for tool paths in the process of cutting machining of robot.5. Due to changes of the robot operation in the spatial position has a great influence on the error of operation ends. In this paper, with the structure and ends of robot cutting loads in certain circumstances, on the basis of the stiffness of the robot system model, using genetic algorithms and take deformation of ends of the robot as the objective function to optimize the spatial position of the robot manipulator tasks, and seek out the best mission space of robot space. |
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